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AssigneeNisshin Steel Co., Ltd.
InventorsYasushi Fukui, Atsushi Ando, Yoshikazu Morita, Masanori Matsuno, Minoru Saito, Hideo Miyake, Masahiko Souda
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An iron-based heat-generating material excellent in oxidation resistance at an elevated temperature which comprises an iron-based alloy capable of generating heat by passing electricity therethrough and a coating of aluminum and oxygen formed on the surface of the alloy, the amount of the oxygen in the coating is less than the stoichiometric amount of oxygen in Al.sub.2 O.sub.3. The material can be prepared by vacuum evaporation of Al onto the surface of the iron-based alloy wherein an oxygen partial pressure in a vacuum gaseous atmosphere for the vacuum evaporation is adjusted so that there is formed on the surface of the alloy a coating consisting of aluminum and oxygen, the amount of the oxygen in the coating being less than the stoichiometric amount of oxygen in Al.sub.2 O.sub.3. When the material is heated in ambient or oxidizing atmosphere, an outermost layer of the coating is rapidly converted to Al.sub.2 O.sub.3.
An iron-based heat-generating material excellent in oxidation resistance at an elevated temperature which comprises an iron-based alloy of the iron-chromium-aluminum series capable of generating heat by passing electricity therethrough and an Al--O coating layer covering a surface of said alloy, wherein said iron-based alloy consists essentially of, by mass %, C in an amount up to 0.2, Si in an amount up to 6, Mn in an amount up to 5, Al 0.4 to 8, Cr in an amount up to 35, N in an amount up to 0.3, the balance Fe and impurities, and wherein said Al--O coating layer consists of uncombined metallic aluminum and Al.sub.2 O.sub.3, the amount of the oxygen in said Al--O coating layer being substantially less than the stoichiometric amount of oxygen in Al.sub.2 O.sub.3.
An iron-based heat-generating material excellent in oxidation resistance at an elevated temperature which comprises an iron-based alloy of the iron-chromium-aluminum series capable of generating heat by passing electricity therethrough and an Al--O coating layer covering a surface of said alloy, and an outermost layer of Al.sub.2 O.sub.3 on said Al--O coating layer, wherein said iron-based alloy comprises, by mass %, C in an amount up to 0.2, Si in an amount up to 6, Mn in an amount up to 5, Al 0.4 to 8, Cr in an amount up to 35, N in an amount up to 0.3, the balance Fe and impurities, and wherein said Al--O coating layer consists of uncombined metallic aluminum and Al.sub.2 O.sub.3, the amount of the oxygen in said coating layer being substantially less than the stoichiometric amount of oxygen in Al.sub.2 O.sub.3.
Dependencies are inferred from the claim text.